1. Technical Field
The present invention relates to an inkjet printer which performs printing on a printing medium in an elongated sheet shape.
2. Background Art
Conventionally, as an inkjet printer performing printing on a printing medium in an elongated sheet shape, an inkjet printer has been known which is structured so that a printing medium before printing is fed out by a feeding mechanism disposed on a rear side of a printer main body, ink is ejected while an inkjet head is relatively moved with respect to the printing medium to perform printing in the printer main body, and the printing medium on which printing has finished is wound by a winding mechanism disposed on a front side of the printer main body (see, for example, Patent Literature 1). In the inkjet printer described above, in order to appropriately feed out or wind up a printing medium without cockles and slackness, a tension applying mechanism which applies a predetermined tension to the printing medium may be provided on a feeding mechanism side or a winding mechanism side (see, for example, Patent Literatures 2 and 3).
A schematic structure of a conventional tension applying mechanism 200 is shown in FIG. 8(a). The tension applying mechanism 200 is structured of a medium arm 203, which is vertically swingable around a rotation shaft 204 that is perpendicular to a feeding direction of a printing medium “M”, and a tension bar 201 which is supported by a tip end part of the medium arm 203 and extended in the perpendicular direction. The medium arm 203 is swung downward depending on its own weight and slackness of the printing medium “M” and thus the tension bar 201 is abutted with the printing medium so that the printing medium is bent and a tension is applied to the printing medium “M”. Further, the tension applying mechanism 200 is arranged with a tension adjustment mechanism 300 which is structured of a ballast arm 301, which is vertically swingable around the rotation shaft 204 and extended in a direction on an opposite side to the tension applying mechanism, and a ballast member 302 which is attached to a tip end of the ballast arm 301. A tension which is applied to the printing medium “M” by the tension applying mechanism 200 is capable of being adjusted by a torque acting on the ballast arm 301 by the ballast member 302.
[Patent Literature 1] Japanese Patent Laid-Open No. 2007-302468
[Patent Literature 2] Japanese Patent Laid-Open No. 2008-279621
[Patent Literature 3] Japanese Patent Laid-Open No. 2003-252501